Hand tool with toothed rotors for dislodging material from a surface

ABSTRACT

A scarifying tool has a plurality of modules, each module consisting of a pair of cutter discs with bevelled teeth, rotatably mounted at an angle to the direction of travel to provide a sideways tearing action on the material to be dislodged as the discs are moved along the surface of the roof. Each module is mounted independently, to provide an independent suspension having several degrees of freedom. Adjustable depth control is provided by moving the discs relative to substrate contacting members to vary the depth of penetration of the cutters below the skids.

BACKGROUND OF THE INVENTION

This invention relates to surface breaking or scarifying tools havingrotatable rollers, discs, or cutters capable of being moved over asurface to be cut or scratched. Such scarifying tools are used toperforate wallpaper.

In removing wallpaper, it is desirable to perforate or scratch thesurface of the wallpaper to allow water or steam to penetrate thesurface of the wallpaper to reach the glue or adhesive adhering thewallpaper to a wall. Generally, such tools have consisted of cutterwheels or spiked rollers, illustrated by the following patents:

U.K. Pat. No. 22540 of 1912,

U.S. Pat. No. 3,389,466, to Parris,

U.S. Pat. No. 2,435,349 to Hall,

U.S. Pat. No. 3,514,814 to Norfleet,

U.S. Pat. No. 4,274,202 to Petrick.

The latter patent assigned to Bonumwerke Tigges and Winckel GmbH &Co.KG, shows a pair of spiked rollers having needle points mounted onelongate rollers, with the pair of rollers inclined to one another insuch a way that if the tool is moved over the surface of wallpaper, eachspike performs two motions similtaneously. That is the motion resultingfrom rotation of the roller, and at an angle thereto, the overall motionof the device. This results in an elongated slot-like hole in thesurface of the wallpaper rather than the pin pricks achieved by rotationof a single roller. The mounting of the pair of rollers, is such that ifthe wall surface is not particularly flat the roller on the high spotswill bite more firmly into the wall and will also tend to control themovement of the device. It will wish to move in a direction normal tothe axis of rotation of the roller on that side. When correctingpressure is applied to the other side, again there will be uneven depthof pricking and the movement will be in the other direction. This hasnot only the undesirable effect of causing the device to move in wavylines, but also reduces the efficiency of the scratching process,because if one side "takes control", the spikes on that side will prickthe wallpaper only leaving pin pricks rather than the elongate slot-likeholes. In addition, the tool described in the Petrick patent has to beheld at a fixed angle to the wall if all of the spikes are to contactthe surface as the tool is moved along the wall. It will be readilyappreciated that changing the angle of the handle relative to the wallwill cause the tool to pivot about those spikes which are distant fromthe handle, thereby allowing the remainder of the spiked rollers to liftclear of the surface. This limits the usefulness of the tool, and withthe necessity for a levelling guide makes it difficult to operate thetool in confined areas.

Another tool showing a pair of inclined rollers is U.S. Pat. No.4,224,726 which teaches the use of pivotally mounted inclined rollersmade up of star wheels to pull a carpet seam together.

U.S. Pat. No. 976,496 to Reiser describes a paper cutter using a pair ofinclined meshing cutting wheels to cut a single score line to facilitateseparation of the cut paper into two portions.

SUMMARY OF THE INVENTION

It is an object of this invention to provide an improved tool capable inone aspect of perforating wallpaper.

In one aspect the invention provides a tool having one or more pairs ofrotatably mounted opposed discs, the discs of each pair being spacedapart from one another and rotatable on axes inclined to one anotherrelative to the direction of travel.

By mounting the discs in opposed pairs across a wallpaper perforatingtool, with each disc capable of perforating the surface of thewallpaper, an improved tool can be provided which is easier to use, asthe discs will not lift off the surface if the angle of the handlerelative to the wall is varied. In addition, the tool is less likely towander over the surface, as each pair of discs provides a compensatingeffect. The ability of this tool to accommodate itself to unevensurfaces, can be improved by mounting each disc or pair of discsindependently.

These and other aspects of the invention will now be described by way ofexample only with reference to the following description of specificembodiments in conjunction with the accompanying drawings.

THE DRAWINGS

FIG. 1 illustrates a perspective view of a first wallpaper perforatingtool, showing one of the modules removed from the tool.

FIG. 2 is a side elevation of one of the modules showing a depth controladjustment.

FIG. 3 is an underside plan view of a module showing the inclination ofthe discs relative to the direction of travel.

FIG. 4 is a front elevation of a module showing the splay angle of thediscs.

FIG. 5 shows an alternative module in side elevation.

FIG. 6 shows a rear elevation of the module of FIG. 5.

FIG. 7 illustrates a module with discs removed, the module being adaptedto fit into a channel member.

FIG. 8 shows an exploded view of a further module.

FIG. 9 is a side elevation of the module of FIG. 8 attached to ascraping tool.

FIG. 10 is a top plan view of a pair of inclined discs.

FIG. 11 is an underside plan view of a tool having pairs of discsmounted across the tool.

FIG. 12 is a side elevation of the tool of FIG. 11.

DETAILED DESCRIPTION OF THE INVENTION

A wallpaper perforating tool 10 has a plurality of modules 11, eachmodule consisting of a pair of cutting discs 12, 13 mounted on axesinclined to one another. The inclination of these axes are best seenfrom FIG. 3. The axes 14, 15 are inclined to one another and the discsare inclined to the direction of travel at an acute angle "a". Thisgives a toe-out effect when the discs are moved by pulling the handle 16in the direction of arrow X. Conversely, this can be regarded as a"toe-in" effect if the handle is pushed in the opposite direction.

Each module 11 is preferably mounted on a flexible member 17 integralwith or attached at one end to the module by an appropriate fastener 18,and at the other end the flexible member can be integral with orattached by an appropriate fastener 20 to the cross-bar 19 of the tool.The tool shown in FIG. 1 has provision for three such modules, althoughit will be appreciated that the cross-bar 19 could be capable ofreceiving any number of flexible members, and hence any number ofmodules.

Each module consists of an inverted U-shaped member having a cross-piece22 and downwardly depending side cheeks 23. The side cheeks arepreferably splayed as shown in FIG. 4 to allow for the mounting of thediscs in a splayed fashion. The bottoms of the side cheeks arepreferably curved at 24 to enable the depth of the cutters to becontrolled by pivoting the handle of the tool relative to the wall.

In addition, a depth control adjustment is provided by mounting thecutters on a resilient mounting 25, in the form of a U-shaped springymember 25, whose position relative to the bottom of the side cheeks canbe varied by movement of a fastener, which is conveniently fastener 18,e.g. a screw which can be moved towards and away from the lower limb 27of the resilient mounting 25.

By suitably shaping the modules and the flexible members 17, it ispossible to provide an independent suspension for each of the pairs ofdiscs, allowing for several degrees of freedom. For example, theflexible member 17 can flex up and down towards and away from a wallsurface to accommodate unevenness in the surface of the wall. Inaddition, the combination of the flexible member and the module canallow for pivotal motion to enable the discs to pivot from side to siderelative to the direction of travel. A further degree of freedom can beprovided in the flexing of the flexible member about its own axis toprovide for rocking of the discs from side to side. This allows for bothup and down, rocking and castoring motion of the discs as they travelacross a wall surface.

The discs can be formed of any convenient material, although for awallpaper perforating tool it will be generally convenient to stamp orpress the discs from sheet steel. If relatively sharp teeth arerequired, as is the case with a wallpaper perforating device, it will begenerally convenient to bevel the edges of the discs before stamping outthe teeth, as the combination of the bevelling and stamping producesrelatively sharp points to the teeth without the need for a separategrinding step. The bevelled nature of these cutting discs is best seenfrom FIG. 4 where the combination of the bevelled edge and the splayangle allows the teeth of the cutting discs to bite into the surface ofthe wallpaper.

The discs are conveniently mounted at an angle "a" of 6 to 18 degrees tothe direction of travel, and more preferably at an angle of 12 to 14degrees to the direction of travel. The discs can be splayed at an angle"b" of about 8 degrees to the vertical as shown in FIG. 4, with a bevelangle of approximately 30 degrees.

Whilst the discs can be of any convenient size, discs of about 25 mmdiameter are particularly suitable to achieve a spacing of about 22 mmbetween module centres. This enables the discs to be formed withdesirable shape of teeth, resulting in a lightweight tool capable ofworking with confined spaces.

The combination of the bevelled teeth, the angle of the discs to thedirection of travel and the splay angle enables the teeth to bite intothe surface of the wallpaper as the tool is pulled down a wall. Theteeth will tear the surface leaving inclined slots, with the tornportion of the paper protruding from the bottom end of the slots to actas a miniature dam for liquid applied to the surface of the paper. Thisenhances the supply per square centimeter of liquid or steam through thewallpaper to the adhesive layer.

By tilting the handle relative to the wall the spacing and angle betweenopposed teeth of a pair of cutters at the point of contact with thesurface can be varied, thereby controlling the penetration of the teethand hence the "aggression" of the discs. Lowering the handle towards thewall reduces the aggression of the discs whilst tilting the handle awayfrom the wall increases the "aggression" of the discs.

The position of the maximum aggression angle can be chosen duringmanufacture by choosing appropriate disc angles. For example, a maximumaggression angle of about 60 degrees between the handle and the wallenables an operator to comfortably use the tool at an angle of about 30degrees to the wall and to control the aggression of the discs byvarying the handle between about 15 degrees and about 45 degrees. Theshape of the wall contacting member for depth control can be chosenduring manufacture to match the optimum range of user angles.

Turning now to FIGS. 5 and 6, there is illustrated an alternativeembodiment of a cutter module. This has a pair of cutter discs 30, 31mounted within splayed sides 32, 33 of a module housing 36. This modulehousing preferably has apertures 38 in each side plate 32, 33 for thereception of a mounting button 39. Each mounting button has a stub axle40 eccentrically mounted with respect to the aperture 38, and may beprovided with a projection or lever 42 to rotate the button and thuscontrol the position of the stub axle relative to the base 43 of theside plate.

Each cutter disc can be mounted on its respective stub axle, and thecutter discs are conveniently held in place by means of a spring 44inserted over each stub axle to thus hold the cutter discs firmly inplace.

The upper portion of the module is conveniently provided with asubstantially rectangular plate 45 spaced apart from the main portion ofthe housing by sides 46 and leaving an opening 47 for the reception of aflexible finger or handle 50.

By this mean, the module can be mounted on a flexible finger, or handle,or the modules can be mounted in parallel by sliding them into a channelmember as shown in FIG. 7. The parallel arrangement of FIG. 7 can beachieved by providing a pimple, on the top of each module so that itwill snap into an appropriate recess 52 on the channel member 53. Bythis means, each module can be provided with a limited amount ofcastoring action relative to the channel.

The mounting of the cutter discs on eccentrically mounted stub axlesenables the depth of penetration of the cutters to be individuallycontrolled by moving the levers 42 and hence moving the stub axles upand down relative to the bottom of the side plates thus controlling thedepth of penetration of the cutters.

By providing a module housing with apertures 38 on the sides thereof,different cutter disc arrangements can be utilized. For example, inplace of the eccentrically mounted stub axles, the discs could bemounted in a similar fashion to that shown in FIGS. 1 through 4, withthe apertures in the side plates receiving a movable insert capable ofmoving up and down relative to the side plate to provide awear-resistant skid which can project down below the position of thecutter discs. Thus instead of adjusting the cutter discs up and downrelative to the side plate, an insert on the side plate can be adjustedup and down relative to the position of the cutters.

In use, the modules of FIGS. 5 and 6 enable the cutters to be mounted inthe toe-out and splayed position, with the cutter discs capable ofindividual depth adjustment. Such cutter discs can be mounted on asimple tool having only one module and a handle, or can be combined invarious combinations to provide a more complex tool having a pluralityof modules mounted thereon, e.g. similar to the tool of FIG. 1.

FIG. 8 shows a further module 55 having a pair of inclined axles 56 ontowhich cutter discs 57 can be mounted. In this arrangement the discs canbe held in place by cover 58 which clips onto the module.

Depth control can be achieved by either moving the axles downwardlyrelative to the cover by screw 59 or by adjusting the position of asurface contacting member 60 attached to the underside of the module. Anintegral shank 61 can be attached to an individual handle or part of atool shown by socket member 62.

By suitably forming the module and shank of a resilient material, thediscs can accommodate themselves to irregularities in the surface ontowhich they are pressed.

FIG. 9 shows how modules 55 can be attached to a scraping tool 56 havinga scraping blade 57 and a mounting plate 58 attached thereto.

Dotted line 60 shows the wall surface when the tool is held at a shallowangle to the wall reducing the aggression of the discs. Broken line 61represents the wall surface when the tool is held at an increased angleto the wall thereby increasing the aggression of the discs.

FIG. 10 shows a top plan view of a pair of cutter discs 63 mounted sothat they are inclined towards a shank portion 64. In this configurationthe teeth are bevelled outwardly as the scarifying action provides anoutward force as the discs move in the direction of arrow X.

The mounting can be formed from folded metal to provide a snap fitportion 65 with a pimple 66 and aperture 67 to hold the disc in place.The shank can be formed as a handle of an individual tool or as acomponent of a multiple disc tool.

FIGS. 11 and 12 show a scarifying tool 70 having a channel member 71 towhich a handle 72 is attached. The limbs 73,74 of the channel member areprovided with clamping bars 75 attachable by fasteners 76. Each clampingbar and the limbs 73, 74 are provided with mating recesses which receiveand clamp in place the legs 77 of disc mountings 78.

Each disc mounting has a stub axle 79 on which a cutting disc 80 ismounted by an appropriate fastener or by swaging the end of the axle totrap the disc in place.

The legs 77 are resiliently mounted by providing a resilient layer orsleeve 82 between the legs and the clamping portions of the limbs andclamping bars. This enables each cutter disc to compensate for surfaceirregularities as it is moved over a working surface.

Each disc can be provided with an adjustable depth control member 83formed as part of the mounting 78.

The discs 80 are mounted in opposed pairs as previously described. Thecentres of these discs lie on a common line although each disc rotateson its own axis inclined to this common line. This enables the handle tobe held at different angles relative to the wall without lifting thediscs of the wall.

The channel member 71 can also be used with a second row of discsmounted on limb 73. In which case, the handle 72 is preferably replacedby a shorter handle or grip enabling the tool to be held flat against awall in the manner of a scrubbing brush.

Additional discs could be mounted on the outer ends 84 of each stub axleso that discs mounted at 84A and 84B would constitute an opposed pair inaddition to the discs mounted at 79A and 79B. Alternatively discs couldbe mounted in opposed pairs in positions such as 84A and 84C.

If desired, a supply of liquid can be provided in conjunction with thewallpaper scarifying tool. For example, a hollow handle may be providedcontaining a supply of water, or detergent, capable of soaking thewallpaper as it is perforated or scratched by the tool. Alternatively,the tool could be provided with a spray head and a supply tube from aliquid reservoir and pump so that liquid could be sprayed onto thewallpaper as it is perforated.

It will be appreciated that the tool can be modified to operate as anice removing tool, for example for removing ice from a car windscreen.In which case, the discs are preferably adapted to perform a grippingand crushing function, rather than a perforating function. The discs canbe formed of a hard plastics material, or can be formed of metal. In apreferred embodiment, the ice removing tool has a plurality of pairs ofdiscs mounted in modules as previously described, with the outer discsbeing formed of plastics, and the inner discs of metal. Depth controlmeans is provided to adjust the depth of the cutter discs relative tothe skids or side plates.

The tool can be provided with a reservoir for a suitable liquid toassist in combating ice situations.

Removable discs enables different types of cutting discs to be used inthe tool. The drawings illustrates sharply serrated discs, and differentshapes of teeth can be chosen depending upon the shape and width of cutrequired. Instead of the sharply serrated discs illustrated in thedrawings, the discs could be abrasive discs having their edges orperipheral flanges coated with an abrasive such as Tungsten Carbide.Discs could be mounted in a wobble configuration with pairs of discsinclined to one another and to the direction of travel but with theadditional variation of wobbling about their main axis of rotation. Sucha configuration is best suited to a module without side guards.

It is to be noted from the drawings that in all embodiments of thepresent invention, all the points of the teeth of all the discs lie on acommon imaginary elliptical sheath. Also, it is to be noted from thedrawings that there is an imaginary straight line on the surface towhich the tool is applied, that passes through all of the circular pathsdescribed by the teeth on all of the discs.

Whilst various embodiments of the tool have been described, it will beappreciated that many other alterations or modifications may be made tothe foregoing without departing from the scope of this invention asexemplified by the following claims.

I claim:
 1. A hand tool for dislodging material from a surface to whichit is adhered, comprising at least one pair of rotatably mounted opposedgripping discs with sharp teeth about their peripheries, the discs ofeach pair being spaced apart from each other and rotatable on axesangled relative to each other and to the direction of travel, all thepoints of the teeth of all the discs lying on a common imaginaryelliptical sheath, the points of the teeth of each disc moving in acircular path upon rotation of the discs, whereby, in use, motion of thetool along a surface will cause all the discs to roll and to impart asideways force on the surface.
 2. A tool as claimed in claim 1, whereinthe discs have bevelled edges.
 3. A tool as claimed in claim 1, whereineach pair of discs are splayed with respect to the working surface.
 4. Atool as claimed in claim 3, wherein a plurality of pairs of discs aremounted across the tool.
 5. A tool as claimed in claim 1 wherein thediscs are resiliently mounted to accommodate unevenness in the surfaceof said layer.
 6. A tool as claimed in claim 5, wherein each pair ofdiscs are mounted on resilient fingers.
 7. A tool as claimed in claim 6,wherein each pair of discs are mounted on a removable module.
 8. A toolas claimed in claim 1, including means for regulating the depth ofpenetration of the discs into said layer.
 9. A tool as claimed in claim8, wherein the discs are provided with a surface contacting memberwhereby the depth of penetration of the discs can be adjusted by movingthe discs relative to the member.
 10. A tool as claimed in claim 1,including a pair of discs mounted on a shank with the pair of discs andshank forming a Y-shaped configuration and the discs angled to thesurface to impart an outwardly sideways force as the tool is pulledalong a wall surface in the direction of the shank.
 11. A hand tool asclaimed in claim 1, there being an imaginary straight line on saidsurface that passes through all said circular paths and is perpendicularto the path of movement of said tool along said surface.